LONG BEACH, Calif. — Chevrolet’s strong start in its return to IndyCar suffered a significant setback Thursday when the manufacturer decided to change the engines for all 11 of its teams before they open the weekend at Long Beach.

The change means all 11 Chevrolet drivers will drop 10 spots on the starting grid before Sunday’s race under an IndyCar rule that prohibits engine changes before each one has completed 1,850 miles.

“This is certainly a decision that was not made lightly,” said Chris Berube, program manager for Chevrolet’s IndyCar effort. “We intently discussed the situation with our partners and our teams prior to determining that this was the best course of action to preserve the integrity of the racing in the IZOD IndyCar Series.”

IndyCar has competing manufacturers for the first time since 2005, with Chevrolet and Lotus jumping into a series that Honda had controlled exclusively the past seven seasons. Lotus is admittedly lagging behind the other two, so it’s been a manufacturers’ battle through the first two events between only Chevy and Honda.

So far, Chevy is the decisive winner.

Chevrolet has won both poles and both races so far this season, and leads the manufacturers’ race with 18 points to Honda’s 12.

IndyCar had previously announced that Lotus driver Sebastien Bourdais would be penalized 10 spots on the grid because his team changed his engine after the April 1 race at Barber. Oriol Servia, who changed his engine before the Barber race, also might need another new Lotus this weekend and also would be subjected to the penalty.

The problem with the Chevrolet engines was discovered following Monday’s open test at Sonoma, where James Hinchliffe had an engine failure. Chevrolet changed his engine, and IndyCar announced he’d be penalized the 10 grid spots.

“This is obviously disappointing, but it is the same for all the Chevy teams and these things happen when you are in development programs,” Chevy owner Michael Andretti said. “Luckily the problem was caught during a test rather than in the middle of a race. It’s unfortunate, but we stand behind Chevy and whatever is needed to continue to set the standard.”

Berube said Chevrolet feared the problem in Hinchcliffe’s engine could affect all of its teams.

“As a result, we feel it is prudent to change all engines prior to the start of the on-track activities this weekend,” he said.

The first practice for IndyCar at Long Beach is Friday morning.

The decision to change engines affects the three-car teams of Penske Racing, which won the first two races of the season behind Helio Castroneves and Will Power, Andretti Autosport, KV Racing and the single-car teams of Ed Carpenter Racing and Panther Racing.

Through the first two races of the season, Honda has had just one major engine issue, when Simon Pagenuad changed his engine before the opener.

Lotus has now changed three — Bourdais, and Servia and Alex Tagliani at Barber — and Servia’s change would be its fourth.